Lumbar Puncture

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Lumbar Puncture
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objectives

• To know the indication and contraindication for
  lumber puncture.
• To know the technique of insertion of the lumber
  puncture.
• Too know the complication of lumber puncture.

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CSF Formation

• 140 ml spinal and cranial CSF
• 30 ml in the spinal cord
• Production is approx. 0.35 ml/min
• Net flow out of ventricles 50 100 ml/day
• Reduces brain weight from 1400 to 50g.

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Indications for Lumbar Puncture

• 1- diagnosis of CNS infection
• 2-suspection of spontaneous subarachnoid
  hemorrhage
• 3- evaluation and diagnosis of demyelinating or
  inflammatory CNS process .

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• 4- infusion of anathesia,chemotherapy,or contrast
  dye into spinal canal
• 5- treatment of idiopathic intracranial
  hypertension

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Infectious Indications

• Fever of unknown origin
• Children 1mo to 3yrs fever, irritability, and
  vomiting. Cannot comfort child
• Over age 3yrs nuchal rigidity, Kernigs sign,
  and Brudzinskis sign
• Petechial rash in a febrile child
• Partially treated children are less likely to be
  febrile or exhibit an altered mental status

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Subarachnoid Hemorrhage

• Diagnosis usually made by CT scan or by blood in
  CSF.
• Initial presentation CT 92-98 accurate
• Later than 24 hr presentation 76 accurate
• After initial leak, CT is usually negative

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Contraindications for LP

• 1-Absolutely contraindicated in the presence of
  infection in the tissues near the puncture site.
• 2-suspesion of increase intracranial pressure
  due to cerebral mass.
• Caution advised when lateralizing signs or signs
  of uncal herniation.

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• 3- uncorrected coagulopathy
• 4-acute spinal cord trauma

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• Technique of insertion

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Equipment

• Spinal needle
• Less than 1 yr 1.5in
• 1yr to middle childhood 2.5in
• Older children and adults 3.5in
• Three-way stopcock
• Manometer
• 4 specimen tubes
• Local anesthesia
• Drapes
• Betadine

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Procedure

• Almost all patients are afraid of an LP.
  Explaining the procedure in advance and
  discussing each step aids in reducing anxiety.
• Inquire about allergies to anesthetics.
• Informed consent.

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positioning

• Performed with the patient in the lateral
  recumbent position. Or sitting upright
• A line connecting the posterior superior iliac
  crest will intersect the midline at approx. the
  L4 spinous process.
• Spinal needles entering the subarachnoid space at
  this point are well below the termination of the
  spinal cord.

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Site of injection

• In the adult, the spinal cord extends to the
  lower level of L1 or the body of L2.
• LP in adults and in older children may be
  performed from L2 to L3 interspace to the L5 to
  S1 interspace.
• At birth, the cord ends at the level of L3.
• LP in infant may be performed at the L4 to L5 or
  L5 to S1 interspace.

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steps

• Position the patient
• Generally performed in the lateral decubitus
  position.
• A pillow is placed under the head to keep it in
  the same plane as the spine.
• Shoulders and hips are positioned. perpendicular
  with the table.
• Lower back should be arched toward practitioner.

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Insertion

1. Sterile gloves MUST be used.
2. Wash back with antiseptic solution.
3. Sterile towel under hips.
4. The skin and deeper subcutaneous tissue are
   infiltrated with local anesthetic.
5. Warn patient of transient discomfort of
   anesthetic.

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• 6-Anesthetizing the deeper subcutaneous tissue
  significantly reduces the procedure discomfort.
• -Some operators not only anesthetize the
  interspinous ligament but also apply local
  anesthesia in a vertical fanning distribution on
  both sides of the spinous processes near the
  lamina.

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• 7-The patient should be told to report any pain
  and should be informed that he or she will feel
  some pressure.
• 8-The needle is placed into the skin in the
  midline parallel to the bed.
• 9-The needle is held with both thumbs and index
  fingers.

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• 10-After the subcutaneous tissue has been
  penetrated, the needle is angled toward the
  umbilicus.
• 11-The bevel of the needle should be facing
  laterally (toward patients side).

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• The ligaments offer resistance to the needle, and
  a pop is often felt as they are penetrated.
• Clear fluid will flow from the needle when the
  subarachnoid space has been penetrated.

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• 11-If bone is encountered, withdrawal into
  subcutaneous tissue and redirect.
• 12-Attach a manometer and record opening
  pressure.
• 13-Turn stopcock and collect fluid.
• Withdrawal needle and place a dressing.

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• Tube 1 is used for determining protein and
  glucose
• Tube 2 is used for microbiologic and cytologic
  studies
• Tube 3 is for cell counts and serologic tests for
  syphilis

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1. Ligament flavum is a strong, elastic, yellow
   membrane covering the interlaminar space between
   the vertebrae.
2. Interspinal ligaments join the inferior and
   superior borders of adjacent spinous processes.
3. Supraspinal ligament connects the spinous
   processes

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Interpretations

• Pressure
• Opening pressure is taken promptly, avoiding
  falsely low values due to leakage through and
  around the needle
• Normal pressure is between 70 and 180 mm H20

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Interpretation

• Appearance
• If CSF is not crystal clear, a pathologic
  condition of the CNS should be suspected
• Compare fluid to water
• Fluid may be clear with as many as 400 RBCs/mm3
  and 200 WBCs/mm3

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Interpretation

• Cells
• WBC counts over 5 cells/mm3 should be taken to
  indicate the presence of pathologic condition
• Polymorphonuclear leukocytes are never seen in
  normal adults
• Neutrophilic pleocytosis is commonly associated
  with bacterial infections or early stages of
  viral infections, tuberculosis, meningitis,
  hematogenous meningitis, and chemical meningitis
  due to foreign bodies.

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Interpretation

• Cells
• Eosinophils are always abnormal and most commonly
  represent a parasite infestation.
• Eosinophils have also been reported in cases of
  subarachnoid hemorrhage, lymphoma, Hodgkins
  disease, brucellosis, fungal meningitis,
  mycoplasma pneumonia infection, measles,
  lymphocytic choriomeningitis, rickettsial
  infections, leukemia, demyelinating disease,
  sarcoiodosis, acute inflammatory demyelinating
  polyneuropathy, allergic reactions, and
  idiopathic eosinophilic meningitis.

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Interpretation

• Cells
• Normal CSF RBCs are less than 10/mm3.
• Counts that are otherwise unexplained may be due
  to a traumatic tap.
• Herpes simplex virus encephalitis may elevate the
  CSF RBC count in many patients.

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Interpretation

• Glucose
• Low CSF glucose concentration indicates increased
  glucose use in the brain and the spinal cord.
• The normal range of CSF glucose is between 50 and
  80 mg/dl
• 60-70 of serum glucose concentration
• Only low concentrations of glucose are
  significance

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Interpretation

• Low CSF Glucose Syndromes

Bacterial meningitis Syphilis
Tuberculous meningitis Chemical meningitis
Fungal meningitis Subarachnoid meningitis
Sarcoidosis Mumps meningitis
Meningeal carcinomatosis Herpes simplex encephalitis
Amebic meningitis Hypoglycemia
Cysticercosis Trichinosis
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Interpretation

• Protein
• Increase in CSF total protein levels are a
  nonspecific abnormality associated with many
  disease states.
• Levels gt 500mg/dl are uncommon and are seen
  mainly in meningitis, in subarachnoid bleeding,
  and with spinal tumors.

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The Traumatic Tap

• It should not be difficult to distinguish between
  subarachnoid hemorrhage and a traumatic tap.
• In traumatic taps, the fluid generally clears
  between 1st and 3rd tubes.

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CSF Analysis with Infections

• Bacterial Infections
• The Gram stain is of great importance, because
  this often dictates the initial choice of
  antibiotic.
• Gram-negative intracellular or extracellular
  diplococci are indicative of Neisseria
  meningitidis
• Small Gram-negative bacilli may include
  Haemophilus influenza, especially in children.
• Gram-positive cocci indicates Streptococcus
  pneumoniae, other Streptococcus species, or
  Staphylococcus.
• 20 of Gram stains may be falsely negative.

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CSF Analysis with Infections

• Bacterial Infections
• While the culture is pending, one may suspect a
  bacterial infection in the presence of an
  elevated opening pressure and a marked
  pleocytosis ranging between 500 and 20,000
  WBCs/mm3.
• The differential count is usually chiefly
  neutrophils.
• A count above 1000 cells/mm3 seldom occurs in
  viral infections.

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CSF Analysis with Infections

• Bacterial Infections
• CSF glucose levels less than 40 mg/dl or less
  than 50 of a simultaneous blood glucose level
  should raise the question of bacterial
  meningitis.
• The CSF protein content in bacterial meningitis
  ranges from 500 to 1500 mg/dl.

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CSF Analysis with Infections

• Viral Studies
• The organisms most commonly isolated in viral
  meningitis are enteroviruses and mumps.
• Enteroviruses summer and fall
• Mumps winter and spring

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CSF Analysis with Infections

• Viral Studies
• WBC count in viral meningitis and encephalitis
  usually 10 to 1000 cells/mm3.
• The differential count is predominantly
  lymphocytic and mononuclear in type.
• Protein levels are usually mildly elevated
• Antibiotic coverage pending culture results may
  be reasonably initiated pending culture results
  if in doubt.

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Complications

• Headache After Lumbar Puncture
• Most common complication
• Occurs 5-30 of all spinal taps
• Usually starts up to 48 hours after to procedure.
• Usually lasts 1-2 days (occas 14 days)

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Complications

• Headache After Lumbar Puncture
• Usually begins within minutes after arising and
  resolves with recumbent position.
• Pain is mild to incapacitating and is usually
  cervical and sub-occipital, but may involve the
  shoulders and the entire cranium.

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Etiology of headache after LP

• 1- leakage of fluid through dural puncture site.
• 2- low CSF pressure.
• 3- some contributing factors as
• The diameter of the needel,the shape of the
  needel,the use of spinal anesthesia

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How to minimize the headache?

• 1-choice of needle standerd Quinck versus
  atraumatic .
• 2- decrease the number of attempts
• 3-reinsersion of the stylet
• 4- bed rest after the proceedures

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• Headache After Lumbar Puncture
• Incidence is higher in younger patients and
  females, and those with headache history.
• Treatment barbiturates, fluids, caffeine (500mg
  in 2 ml NS IV push) more common 500mg in 2 L over
  1 hr.

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• Thank you